title: Two adjacent nucleotide-binding site-leucine-rich repeat class genes are required to confer Pikm-specific rice blast resistance.
abstract: The rice blast resistance gene Pikm was cloned by a map-based cloning strategy. High-resolution genetic mapping and sequencing of the gene region in the Pikm-containing cultivar Tsuyuake narrowed down the candidate region to a 131-kb genomic interval. Sequence analysis predicted two adjacently arranged resistance-like genes, Pikm1-TS and Pikm2-TS, within this candidate region. These genes encoded proteins with a nucleotide-binding site (NBS) and leucine-rich repeats (LRRs) and were considered the most probable candidates for Pikm. However, genetic complementation analysis of transgenic lines individually carrying these two genes negated the possibility that either Pikm1-TS or Pikm2-TS alone was Pikm. Instead, it was revealed that transgenic lines carrying both of these genes expressed blast resistance. The results of the complementation analysis and an evaluation of the resistance specificity of the transgenic lines to blast isolates demonstrated that Pikm-specific resistance is conferred by cooperation of Pikm1-TS and Pikm2-TS. Although these two genes are not homologous with each other, they both contain all the conserved motifs necessary for an NBS-LRR class gene to function independently as a resistance gene.
authors.affiliation: QTL Genomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan. ashikawa@affrc.go.jp
authors.forename: Ikuo
authors.initials: I
authors.lastname: Ashikawa
authors.forename: Nagao
authors.initials: N
authors.lastname: Hayashi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamane
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kanamori
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Wu
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Ono
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D000090263:Leucine-Rich Repeat Proteins; D020082:Magnaporthe; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D030821:Plants, Genetically Modified; D011506:Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D000090263:Leucine-Rich Repeat Proteins; D009711:Nucleotides; D011506:Proteins